[Michael] found a very, very cheap toy quadcopter in his local shop, and issued a challenge to himself. He would reverse engineer this quadcopter’s radio protocol. His four-post series of ...

A new version of Ukraine's Shrike FPV attack drone can sink underwater, then re-emerge to carry out an attack. It might be the next generation of ambush drons.

This makes it arguably more of an (indoor) toy than a DJI competitor, but as a DIY quadcopter project it definitely is a lot of fun, while costing a lot less than most hobbies.